This invention relates to commutators for dynamoelectric machines. In such commutators, a plurality of electrically conducting segments are rotated by the armature consecutively past one or more stationary, electrically conducting brushes to commutate the armature current during machine operation. It has been found, however, that the operation of such a commutator is a source of audible noise as the brushes slide across the commutator segment surfaces, and particularly as the brushes move from each commutator segment to the next. As the commutator segments are rotated past the brushes, each brush traces a contact path across the surface of the segment. In standard commutator construction, segments are of equal size, shape and spacing so that these contact paths are all of substantially equal length. Therefore, as the armature rotates at a substantially constant speed, the changes in audible sound caused by the brush traversing from one segment to the next occur at a substantially constant frequency. The effect of this substantially constant frequency is to render the audible brush noise of the motor substantially tonal in character; and tonal noises appear to be more annoying and objectionable to a listener than broad spectrum frequency noises of substantially the same average noise power.